The present invention relates to stair stringers, and more particularly to an assembly for constructing a stair stringer assembly and a stairway assembly.
Conventional stairways, especially in residential construction, include a stringer made from a 2×12 piece of wood, with portions of the stringer cut away to define the rise and run of each step. This construction requires that each triangular portion of wood removed be marked and cut separately, involving a great deal of labor and presenting numerous opportunities for error and injury—even for the most skilled carpenter. It also results in a stringer having an effective structural thickness of less than half the thickness of the original 2×12 piece of lumber, with about one-quarter of the original 2×12 piece being scrapped.
A number of attempts have been made at producing stairs more efficiently and accurately. Most of these attempts incorporate preassembled portions of stringers, portions of stairways, or complete prefabricated stairways. These products reduce some of the on-the-job calculating and cutting that is required with conventional stringers, but they also reduce, and in some cases eliminate, the ability of the installer to accommodate for variables found in the typical building environment, such as variations in the floor to ceiling height and variations in the tread and riser materials.
U.S. Pat. No. 6,088,977 discloses a plurality of L-shaped brackets that can be used to construct a stringer. Each L-shaped bracket includes markings to indicate rise and run dimensions. The stringer is constructed by separately aligning and attaching each individual bracket onto a conventional 2×6 board using the bracket's rise and run dimensions. Treads and risers are attached to the stringers to complete the stairway. This system eliminates most of the cutting issues in constructing the stringer, but suffers from disadvantages as each bracket must be carefully measured before attaching it to the 2×6 board, which increases installation time and leaves a significant potential for error in the placement of each bracket. As a result, stairway manufacturers, contractors and do-it-yourself installers are continually searching for a simple, efficient and accurate way to construct stairway stringers and stairways.